$Unique_ID{BRK03889} $Pretitle{} $Title{Joubert Syndrome} $Subject{Joubert Syndrome Cerebellarparenchymal Disorder IV Cerebellar Vermis Aplasia Cerebellar Vermis Agenesis-Neurological Abnormalities Cerebellar Vermis Aplasia Cerebelloparenchymal Disorder IV Familial Chorireninal Coloboma-Joubert Syndrome Hyperpnea, Episodic-Abnormal Eye Movement-Ataxia-Retardation Joubert-Bolthauser Syndrome Kidneys, Cystic-Retinal Aplasia Joubert Syndrome Vermis Cerebellar Agenesis Polydactyly-Joubert Syndrome Retinal Aplastic-Cystic Kidneys-Joubert Syndrome Vermis Aplasia Vermis Cerebellar Agenesis Dandy Walker Syndrome Leber's Congenital Amaurosis Hydrocephalus } $Volume{} $Log{} Copyright (C) 1986, 1988, 1990, 1992 National Organization for Rare Disorders, Inc. 20: Joubert Syndrome ** IMPORTANT ** It is possible that the main title of the article (Joubert Syndrome) is not the name you expected. Please check the SYNONYMS listing to find the alternate name and disorder subdivisions covered by this article. Synonyms Cerebellarparenchymal Disorder IV Cerebellar Vermis Aplasia Cerebellar Vermis Agenesis-Neurological Abnormalities Cerebellar Vermis Aplasia Cerebelloparenchymal Disorder IV Familial Chorireninal Coloboma-Joubert Syndrome Hyperpnea, Episodic-Abnormal Eye Movement-Ataxia-Retardation Joubert-Bolthauser Syndrome Kidneys, Cystic-Retinal Aplasia Joubert Syndrome Vermis Cerebellar Agenesis Polydactyly-Joubert Syndrome Retinal Aplastic-Cystic Kidneys-Joubert Syndrome Vermis Aplasia Vermis Cerebellar Agenesis Information on the following diseases can be found in the Related Disorders section of this report: Dandy Walker Syndrome Leber's Congenital Amaurosis Hydrocephalus General Discussion ** REMINDER ** The Information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Joubert Syndrome is a very rare neurological disorder involving a malformation of the area of the brain that controls balance and coordination. Generally motor activity is slowed (psychomotor retardation) and there are abnormal eye movements. Respiratory irregularities, including rapid panting, may occur during infancy. Symptoms Joubert Syndrome is characterized by periods of cessation of breathing during sleep (sleep apnea). Periods of deep, abnormal breathing are common in infants and may be triggered by emotional stimulation such as crying. Unusually deep inhalations also occur. These respiratory irregularities generally decrease as the infant gets older. Abnormal eye movements such as irregular jerking, eye rolling or crossing of the eyes may be present. Impaired coordination of movement and walking (ataxia), and difficulty in controlling the range of voluntary movement (dysmetria) are characteristic of Joubert Syndrome. Tremors may also be observed. Muscle weakness may be accompanied by clumsy or rapid alternating movements. Mental retardation may also occur. Causes The exact cause of Joubert Syndrome is not known. This disorder may be inherited as an autosomal recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal. Affected Population Joubert Syndrome is extremely rare and generally appears during infancy. It is estimated that only 10 cases occur each year in the United States. Both males and females can be affected, and the disorder can occur more than once in the same family. Related Disorders Symptoms of the following disorders can be similar to those of Joubert Syndrome. Comparisons may be useful for a differential diagnosis: Dandy-Walker Syndrome is a rare inherited disorder that is characterized by congenital hydrocephalus that is an accumulation of fluid in the brain and an increase of pressure within the skull. This swelling of the head is generally accompanied by headaches, visual disturbances that come and go and swelling of the eyes (papilledema). (For more information, choose "Dandy Walker" as your search term in the Rare Disease Database.) Leber's Congenital Amaurosis (LCA) is a rare inherited disorder that affects the eyes. Infants are born without the cells that gather light in the retina of the eye. It is characterized by blindness at birth, roving eye movements and pupils that react poorly to light and dilate widely in darkness. Often the eyes are deeply set and the infant will rub the eyes to stimulate the retina to produce light (oculodigital stimulation). This disorder is frequently associated with a family history of loss of eye muscle coordination. (For more information on this disorder, choose "Leber's Congenital Amaurosis" as your search term in the Rare Disease Database.) Hydrocephalus is a condition in which enlarged (dilated) cerebral ventricles in the brain restrict the normal flow of cerebrospinal fluid (CSF). The cerebrospinal fluid accumulates in the skull and puts pressure on the brain tissue. The characteristic features in children include an enlarged head, a bulging forehead, a thin transparent scalp and a downward gaze. Other symptoms may include convulsions, abnormal reflexes, a slowed heartbeat and respiratory rate, headache and visual problems. (For more information on this disorder, choose "Hydrocephalus" as your search term in the Rare Disease Database.) Therapies: Standard The treatment for Joubert Syndrome is symptomatic and supportive. Special education services and physical therapy may be of benefit to children with this disorder. When hydrocephalus occurs, a shunt may be recommended to facilitate the drainage of fluid from the brain. Genetic counseling may be of benefit for Joubert Syndrome families. Therapies: Investigational Research on birth defects and their causes is ongoing. The National Institutes of Health (NIH) is sponsoring the Human Genome Project that is aimed at mapping every gene in the human body and learning why they sometimes malfunction. It is hoped that this new knowledge will lead to prevention and treatment of genetic disorders in the future. This disease entry is based upon medical information available through September 1992. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Joubert Syndrome, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Joubert's Syndrome Parents in Touch Network 12348 Summer Meadow Road Rock, MI 49880 (906) 359-4707 Joubert Syndrome 5636 Secor Rd, #11 Toledo, OH 43627 NIH/National Institute of Neurological Disorders & Stroke (NINDS) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5751 (800) 352-9424 Children's Brain Diseases Foundation for Research 350 Parnassus, Suite 900 San Francisco, CA 94117 (415) 566-5402 (415) 565-6259 David B. Flannery, M.D., Director Division of Medical Genetics Department of Pediatrics BG-121 Medical College of Georgia Augusta, GA 30912 (404) 721-2809 For Genetic Information and Genetic Counseling Referrals: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References MENDELIAN INHERITANCE IN MAN, 10th Ed.: Victor A. McKusick, Editor: Johns Hopkins University Press, 1992. Pp. 1487. BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief; Blackwell Scientific Publications, 1990. Pp. 995-996. JOUBERT'S SYNDROME WITH RETINAL DYSPLASIA: NEONATAL TACHYPNOEA AS THE CLUE TO A GENETIC BRAIN-EYE MALFORMATION, M.D. King et al.; Arch Dis Child (August 1984; 59(8)): Pp. 709-718. DYSMORPHIC FEATURES OF JOUBERT SYNDROME, L.A. Squires et al.; Dysmorphol Clin Genet (May 1991; 5): Pp. 77-79. JOUBERT'S SYNDROME ASSOCIATED WITH CONGENITAL FIBROSIS AND HISTIDINEMA, R.E. Appleton et al.; Arch Neurol (May 1989; 46(5)): Pp. 579-582.